def __init__(self, storage=None):
self._dict = dict()
self._lock = Lock()
self._storage = Storage(State.__FILENAME)
if storage is not None:
self._storage = storage
self._refresh()
class State(object):
__FILENAME = "pypaxos.state"
def __init__(self, storage=None):
self._dict = dict()
self._lock = Lock()
self._storage = Storage(State.__FILENAME)
if storage is not None:
self._storage = storage
self._refresh()
def read(self, key):
return self._dict[key]
def write(self, key, value):
self._dict[key] = value
self._flush()
def set_default(self, key, value):
if not key in self._dict:
self.write(key, value)
def _refresh(self):
STATE_LOCK.acquire()
try:
self._dict = load(self._storage.get()) or dict()
except FileNotFoundError:
self._dict = dict()
finally:
STATE_LOCK.release()
def _flush(self):
STATE_LOCK.acquire()
try:
self._storage.put(dump(self._dict))
finally:
STATE_LOCK.release()
def __init__(self, storage=None):
self._lock = Lock()
self._storage = Storage(Ledger.__FILENAME)
if storage is not None:
self._storage = storage
class Ledger(object):
__FILENAME = "pypaxos.ledger"
def __init__(self, storage=None):
self._lock = Lock()
self._storage = Storage(Ledger.__FILENAME)
if storage is not None:
self._storage = storage
def append(self, ledger_entry):
LEDGER_LOCK.acquire()
try:
self._append(ledger_entry)
finally:
LEDGER_LOCK.release()
def _append(self, ledger_entry):
self._storage.append(ledger_entry)
def extend(self, ledger_entries):
last = LedgerEntry(-1)
LEDGER_LOCK.acquire()
try:
if len(self._storage) > 0:
last = LedgerEntry(*self._storage[len(self._storage) - 1].split(LedgerEntry.SEPARATOR))
for entry in [n for n in ledger_entries if n.number > last.number]:
self._append(entry)
finally:
LEDGER_LOCK.release()
def get_range(self, start, end=None):
LEDGER_LOCK.acquire()
try:
start_index = self._get_index(start)
end_index = self._get_index(end)
storage_range = [LedgerEntry(*l.split(LedgerEntry.SEPARATOR)) for l in self._storage[start_index:end_index]]
finally:
LEDGER_LOCK.release()
return storage_range
def _get_index(self, proposal):
if proposal is None:
return None
# TODO: O(log n) Binary Search
for index, line in enumerate(self._storage):
entry = LedgerEntry(*line.split(LedgerEntry.SEPARATOR))
if entry.number == proposal.number:
return index
return None
def __iter__(self):
for line in self._storage:
yield LedgerEntry(*line.split(LedgerEntry.SEPARATOR))
def __len__(self):
return len(self._storage)
